It's a point-and click adventure game from Germany, in the grand tradition of Space Quest and Leisure Suit Larry. The interface is crisp, and the puzzles are generally variations of "talk to this guy, use this thing, combine these objects." That having been said, it's got a weird sense of humor that reminds me of the old school Sierra adventures, complete with a dude with a heavy German accent playing a folk song introduction to each chapter.
WARNING: Some of the humor, especially in the middle and third chapter, can get rather. . . "Dead Baby" ish. The only ones that really upset me in the end are a series of horrible things you end up doing to people in the third game in order to pursue a quest that turns out to have been pointless the entire ttime. (And then there were the baby dolphins. :( ) Plus a few moments of grossout humor here and there, mostly based around the fact that the game is set on a garbage planet with all that entails.
The main character is kind of a jerk who is saved from being an outright antihero simply because there are a few lines that he won't cross. He spends most of his time being a self-centered jerk who mooches off of other people, steals everything that isn't nailed down, and screws people over left and right in pursuit of his own goal and Goal. So in other words, he's an adventure game hero.
Gameplay wise, there are a few puzzles which are completely incomprehensible without a walkthrough or guide. Par for the course for an adventure game, of course, but after playing a few Telltale Games adventures, the older model of "point and click trial and error" gameplay feels a bit dated. One Godsend: the more irritating puzzles include a "skip" option that will allow you to pass the puzzle without completing it, if you get frustrated and just want to go on to the next part of the plot.
One huge pet peeve: "F5 IS QUICK SAVE. F9 IS QUICK LOAD." This is the mantra that most game makers use. This is because it means that there is a minimum chance of accidentally bumping the other button and either saving over your game when you didn't mean to, or quick loading when you didn't want to. Deponia uses "F9 FOR QUICK SAVE, F10 FOR QUICK LOAD." This cost me a bunch of progress at one point when I accidentally bumped the F10 key when I realized I'd gone a while without saving and tried to quick-save.
All in all, I enjoyed it, I was glad I played it. Supposedly there's a New Game Plus mode, and some collectables you can pick up, but I don't think I have the desire to revisit this game any time soon: nothing against it in general, just that linear adventure games tend not to be as fun the second time around.
Pick it up on sale.